Halogen substituted alkenylthioalkyl esters of phosphorus acids



aren't amazes Patented Feb. 6, 1862 hire 3,020,305 HALOGEN SUBSTITUTEDALKENYLTHIOALKYL ESTERS OF PHOSPHORUS ACIDS John P. Chupp, Nitro, W.Va., assignor to Monsanto Chemical Company, St. Louis, Mo., acorporation of Delaware No Drawing. Filed Aug. 25, 1958, Ser. No.757,124

11 Claims. (Cl. 260-461) This invention relates to a new class of organophos- 'phorus compounds, insecticidical compositions containing them andto methods of destroying insects. More particularly, the inventionrelates to halogen substituted alkenylthioalkyl esters of phosphorusacids, especially phosphorothioates.

The new compounds may be conveniently represented by the general formulawhere R and R are hydrocarbon radicals, preferably lower alkyl radicals,X and X are oxygen or sulfur, at least one preferably being sulfur, A isan alkylene radical, preferably methylene, and R is a halogensubstituted alkenyl radical. Examples of R and R are methyl, ethyl,propyl, isopropyl, butyl, isobutyl, sec. butyl, amyl, isoamyl, allyl,phenyl, cyclohexyl, hexyl, octyl and decyl.

The radicals designated R may be selected from a variety of halogensubstituted alkenyl radicals but is preferably a halogen substitutedlower alkenyl group, as for example 2-chloroallyl, 2-bromoallyl,3-chloroallyl, 3-iodoallyl, 2-fluoro-3-chloroallyl, 3-bromo-2-bute'nyl,2,3-dichloroallyl, 3,3-dichloroallyl, 2,3-dichloro-2-butenyl, 2,3-diodo-Z-butenyl, 2,3-dichloro-4-bromobutenyl and I 2,3,3-trichloroallyl.

'While the new compounds are particularly valuable systemicinsecticides, they have other uses. Thus they comprise useful mineraloil adjuvants in which they serve as antioxidants and to increasetheload carrying capacity of mineral oil lubricants. The method ofsynthesis can vary as hereinafter described. The invention will be fullyunderstood and apparent from the detailed examples which follow:

EXAMPLE 1 Into a suitable reactor is charged 15.7 grams (0.10 mole) of2-chloroallyl thiomethyl chloride, 22.3 grams (0.11 mole) of ammonium0,0-diethyl phosphorodithioate and 100 ml. of acetone and the mixturerefluxed for 4 hours. After cooling, the precipitated ammonium chlorideis filtered and the salt cake washed with acetone. The filtrate is thenstripped of acetone under vacuum, washed with water and taken up inmethylene dichloride. The methylene dichloride solution is washed withwater and then stripped to 100 C./5 mm. The 0,0-diethyl S-(2-chloroal1ylthiomethyl) phosphorodithioate remains as an amber liquidin 96.0% yield. Analysis: 9.8% phosphorus, 11.9% chlorine and 31.3%sulfur as compared to 10.1% phosphorus, 11.6% chlorine and 31.4% sulfurcalculated for C H ClO PS EXAMPLE 2 Substituting 20.6 grams (0.11 mole)of ammonium 0,0-diethyl phosphorothioate for the phosphorodithioate inthe procedure of Example 1, 0,0-diethylS-(2-chloroallylthiomethyl)phosphorothioate is obtained as an amberliquid in 93.0% yield. Analysis: 9.9% phosphorus and 22.0% sulfur ascompared to 10.6% phosphorus and 22.0% sulfur calculated for C H ClO PSOther examples prepared by the same procedure as in Example 1 butsubstituting the appropriate reactants are summarized in tabular formbelow. All are amber oils.

Table I Analysis Example No. Product Calcd, Found,

perpercent cent P 9.1 8.9 3 0,0-DlethylS-(3,3-d.ichl0roallylthiomethyl)phosphorodithioate. g g 4 0,0-DiethylS-(3,3-dichloroallylthir 19.7 20.2 omethyl)phosphorothioate. g 5 8 8 g 50,0-Diethyl S-(3-ehloroallylthl0' Q 1.2 31.5 methyl)phosphorodithioate.g 3 g 5 g 6 0,0-Diethyl S-(3-chloroa1lylthiot 22.0 22.6methyDphosphorothwate. g 12 2 12 0 7 0,0-Dimethyl S-(3-ehl0r0allylthio-1M 34.5 35.2 methyl)phosphorodithloate. g 3 g 1 s0,0-DiisopropylS-(3-chloroallylthi- 28.7 28.4 Iomethyl)phosphorodithloate. g 3 g g 9 0,0-Dietl1ylS-(3-el1loro-2-butenylthiornethyDphosphorodithioate. g g 10 0,0-DiethylS-(3-chlo1'0-2butenyl- 10.2 9.3 thiomethyl)phosphorothioate. 21. 0 21. 911 0,0-Dimethyl S-(2-chl0roallylthiomethyl)phosphorodithioate. 19 3g g 112 0,0-Dimethyl S-(3,3-dichloroallylthiomethyl)phosphorodithioate. E g

EXAMPLE 13 A mixture of 15.2 grams (0.1 mole) of2-(2-chloroallylthio)ethanol, 19.7 grams (0.1 mole) of 0,0-diethylphosphorochloridothioate, 10.1 grams (0.1 mole) of triethylamine and 100ml. of benzene is prepared and the mixture heated at refluxingtemperature for 4 hours in the presence of 0.2 gram of finely dividedcopper powder. The salt cake is filtered, washed with benzene and thefiltrate and washings combined to be subsequently washed with 3% sodiumcarbonate solution, then twice with successive water washes. The solventis stripped ofr to yield as the residue 0,0-diethy1O-2-(2-chloroallylthio)ethyl phosphorothioate as a mobile liquid.

EXAMPLE 14 Substituting, 0.1 mole of diethyl phosphorochloridate fordiethyl phosphorochloridothioate in the foregoing procedure yieldsdiethyl 2-(2-chloroallylthio)ethyl phosphate.

EXAMPLE 15 A mixture of grams (0.43 mole) of 0,0-diethylphosphorodithioic acid and 47.0 grams (0.43 mole) of2-chloroallylmercaptan is prepared and 38 grams (0.46 mole) of 37%aqueous formaldehyde added during 45 minutes. The reactants are stirredfor about 3 hours without heating and then stirred at about C. for 3hours longer. The product is separated from the water layer, washedtwice with water and stripped of volatiles by heating on a steam bath invacuo. The residue, 0,0-diethylS-(2-chloroallylthiomethyl)phosphorodithioate is an amber liquid.

EXAMPLE 16 A mixture of 17.1 grams (0.10 mole) of 2-chloroallylthioethyl chloride, 22.3 grams (0.11 mole) of ammonium 0,0-diethylphosphorodithioate and ml. of acetone is prepared and the mixturerefluxed for 4 hours. After cooling, the precipitated ammonium chlorideis filtered and the salt cake washed with acetone. The filtrate is thenstripped of acetone under vacuum, washed with water and taken up inmethylene dichloride. The methylene dichloride solution is washed withwater and then stripped to 100 C./ mm. The 0,0-diethylS-(2-chloroallylthioethyl)phosphorodithioate remains as an arnberliquid.

EXAMPLE 17 Substituting 20.6 grams (0.11 mole) of ammonium 0,0-diethylphosphorothioate for the phosphorodithioate in the procedure of Example16, 0,0-diethyl S-(2- chloroallylthioethyl)phosphorothioate is obtainedas a dark amber liquid.

The new compounds are useful for destroying a variety of insect pests bycontacting the insect in its environment either directly or indirectlythrough translocation within the plant. The compounds may be applied insolution, emulsion, water dispersion or as a dust formulation whereinthe active ingredient is distributed over a dry, freeflowing powder, asfor example clays, including bentonite and attapulgite, or suchmaterials as talc, diatomaceous earth, Fullers earth, chalk or calciumcarbonate. Although most of the toxicants are insoluble in water, theyare soluble in common organic solvents. They may be dispersed directlyin water or a solution in an organic solvent emulsified in aqueousmedium by the aid of a dispersing agent. As dispersing and wettingagents there may be employed soft or hard sodium or potassium soaps,alkylated aromatic sodium sulfonate, such as sodium dodecylbenzenesulfonate, an amine salt, as for example dibutylammonium dodecylbenzenesulfonate, alkali metal salts of sulfated fatty alcohols, ethylene oxidecondensa tion products of alkyl phenols, or tall oil or highermercaptans and other dispersing and wetting agents. Addition of alkylsulfates, as for example methyl sulfate, is advantageous in someinstances.

The required concentrations of active ingredients are small because ofthe high effectiveness of the new compounds. Sprays for application toagricultural crops may suitably be applied at concentrations of0.001-1.0%. An acetone solution of 0,0-diethylS-(2-chloroallylthiomethyl)phosphorodithioate applied as a residualtreatment to filter paper at a rate of 1 mg. per square foot gives 100%kill of the red flour beetle (Tribolium castaneum). Kills of 100% arealso obtained from acetone solutions of 0,0-diethylS-(2-chloroallylthiomethyl)- phosphorothioate applied at the rate of 5mg. per square foot. Other insects to which the compounds are extremelytoxic include yellow fever mosquito (Aedes aegypti), Southern armyworm(Prodenia eridania), and plum curculio (Conotrachelus nenuphar).

Systemic activity is demonstrated by immersing excised stems of beanplants in emulsions of the chemicals for 3 days. The leaves are then out01f, infected with the chosen insects and percent kill noted after 48hours. In emulsions at concentrations of 0.1% and even at 0.001% orlower, high percent kills are noted against such insects as two-spottedmite (Tetranychus telarius), Mexican bean beetle (Epilachna varivestis)and cotton aphid (Aphis gossypii).

It is intended to cover all changes and modifications of the examples ofthe invention herein chosen for purposes of disclosure which do notconstitute departures from the spirit and scope of the invention.

What is claimed is:

1. A compound of the structure wherein R and R; each represent a loweralkyl radical,

4 X and X represent a chalkogen having atomic weight less than 40, Arepresents a lower alkylene radical and R represents a-halogensubstituted lower 2-alkenyl radical.

. 2. A compound of the structure where R and R represent lower alkyl, Xand X represent a chalkogen having atomic weight less than 40, nrepresents an integer at least 1 but less than 3 and R represents ahalogen substituted allyl radical.

3. A compound'of the structure wherein R and R each represent a loweralkyl radical and R is a halogen substituted allyl radical.

4. A compound of the structure wherein R and R each represent a loweralkyl radical and R is a halogen substituted allyl radical.

5. A compound of the structure wherein R and R each represent a loweralkyl radical and R is a halogen substituted allyl radical.

6. 0,0-diethyl S-(2-chloroally1thiornethyl)phosphorodithioate.

7. 0,0-diethyl S-(2-chloroallylthiomethyl)phosphorothioate.

8. 0,0-diethyl 'S-(3,S-dichloroallylthiomethyl)phosphorodithioate.

9. 0,0-diisopropyl S-(3-chloroallylthiomethyl)phosphorothioate.

10. 0,0-diethyl S-(3-chloro-2-butenylthiomethyl)phosphorodithioate.

11. 0,0-dimethyl S-(3,3-dichloroallylthiomethyl)phosphorodithioate.

References Cited in the file of this patent UNITED STATES PATENTS2,661,366 Gamrath et al. Dec. 1, 1953 2,678,329 Gamrath et a1 May 11,1954 2,786,009 Pianfetti et al Mar. 19, 1957 2,861,912 Sallman Nov. 25,1958 FOREIGN PATENTS 1,113,363 France Dec. 5, 1955 795,340 Great BritainMay 21, 1958 OTHER REFERENCES Clark et al.: I. Agr. Food Chem, vol. III,pp. 834-6 (1955),

1. A COMPOUND OF THE STRUCTURE